Agriculture Reference
In-Depth Information
4
A Crop Stress Index to Predict
Climatic Effects on Row-Crop
Agriculture in the U.S. North
Central Region
Stuart H. Gage, Julie E. Doll, and Gene R. Safir
Corn (
Zea mays
L.) and soybean (
Glycine max
L.) are major U.S. grain crops with
38.6 million and 31.0 million ha (95.4 and 76.5 million acres) planted in 2013,
respectively (NASS 2014a). These two crops support both local demand and inter-
national agricultural exports and greatly contribute to the U.S. economy. The value
of production for corn and soybean in the United States has increased markedly in
recent years and for 2012 was estimated at $77.4 billion and $43.2 billion, respec-
tively (NASS 2014b). Corn accounted for 41% of the value of production of all
U.S. ield crops in 2012 (NASS 2014b). The United States is the world's largest
exporter of corn, exporting 46.6 Tg (1.8 billion bushels) from the 2010 harvest of
317 Tg (12.5 billion bushels) (ERS 2011a). The U.S. North Central Region (NCR)
(Fig. 4.1), often called the Corn Belt due to the success of its dominant crop (Hudson
1994), contains some of the most productive cropland in the world, growing over
80% of U.S. corn and soybean. The agricultural importance of this region will only
continue to grow as demand for food, fuel, and fiber increases across the globe.
Natural vegetation in the NCR ranges from eastern deciduous forest in the
north and east to tallgrass prairie in the central portion to shortgrass prairie in the
west (Bailey 1998). Today, much of the NCR has been transformed to croplands
(Fig. 4.1). Of its 228 million ha (563 million acres), 39.8% are row crops; corn and
soybean account for 34% and 29%, respectively, of this area (NASS 2009a). The
Kellogg Biological Station Long-term Ecological Research Site (KBS LTER) lies
in the middle of the latitudinal range of the Corn Belt (Robertson and Hamilton
2015, Chapter 1 in this volume) and thus represents the climate stresses typical for
row crops such as corn and soybean. The geographic position of KBS provides an
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